As is known, MCP-1 (Monocyte Chemotactic Protein-1) is a protein belonging to the β subfamily of chemokines. MCP-1 has powerful chemotactic action on monocytes and exerts its action also on T lymphocytes, mastocytes and basophils (Rollins B. J., Chemokines, Blood 1997; 90: 909-928; M. Baggiolini, Chemokines and leukocyte traffic, Nature 1998; 392: 565-568).
Other chemokines belonging to the β subfamily are, for example, MCP-2 (Monocyte Chemotactic Protein-2), MCP-3, MCP-4, MIP-1α and MIP-1β, RANTES.
The β subfamily differs from the α subfamily in that, in the structure, the first two cysteines are adjacent for the β subfamily, whereas they are separated by an intervening amino acid for the α subfamily.
MCP-1 is produced by various types of cells (leukocytes, platelets, fibroblasts, endothelial cells and smooth muscle cells).
Among all the known chemokines, MCP-1 shows the highest specificity for monocytes and macrophages, for which it constitutes not only a chemotactic factor but also an activation stimulus, consequently inducing processes for producing numerous inflammatory factors (superoxides, arachidonic acid and derivatives, cytokines/chemokines) and amplifying the phagocytic activity.
The secretion of chemokines in general, and of MCP-1 in particular, is typically induced by various pro-inflammatory factors, for instance interleukin-1 (IL-1), interleukin-2 (IL-2), TNFα (Tumour Necrosis Factor α), interferon-γ and bacterial lipopolysaccharide (LPS).
Prevention of the inflammatory response by blocking the chemokine/chemokine receptor system represents one of the main targets of pharmacological intervention (Gerard C. and Rollins B. J., Chemokines and disease. Nature Immunol. 2001; 2:108-115).
There is much evidence to suggest that MCP-1 plays a key role during inflammatory processes and has been indicated as a new and validated target in various pathologies.
Evidence of a considerable physiopathological contribution of MCP-1 has been obtained in the case of patients with articular and renal inflammatory diseases (rheumatoid arthritis, lupus nephritis, diabetic nephropathy and rejection following transplant).
However, more recently, MCP-1 has been indicated among the factors involved in inflammatory pathologies of the CNS (multiple sclerosis, Alzheimer's disease, HIV-associated dementia) and other pathologies and conditions, with and without an obvious inflammatory component, including atopic dermatitis, colitis, interstitial lung pathologies, restenosis, atherosclerosis, complications following a surgical intervention (for instance angioplasty, arterectomy, transplant, organ and/or tissue replacement, prosthesis implant), cancer (adenomas, carcinomas and metastases) and even metabolic diseases such as insulin resistance and obesity.
In addition, despite the fact that the chemokine system is involved in controlling and overcoming viral infections, recent studies have demonstrated that the response of certain chemokines, and in particular of MCP-1, may have a harmful role in the case of host-pathogen interactions. In particular, MCP-1 has been indicated among the chemokines that contribute towards organ and tissue damage in pathologies mediated by alpha viruses characterized by monocyte/macrophage infiltration in the joints and muscles (Mahalingam S. et al. Chemokines and viruses: friend or foes? Trends in Microbiology 2003; 11: 383-391; Rulli N. et al. Ross River Virus: molecular and cellular aspects of disease pathogenesis. 2005; 107: 329-342).
Monocytes are the main precursors of macrophages and dendritic cells, and play a critical role as mediators of inflammatory processes. CX3CR1, with its ligand CX3CL1 (fractalkine), represents a key factor in regulating the migration and adhesiveness of monocytes. CX3CR1 is expressed in monocytes, whereas CX3CL1 is a transmembrane chemokine in endothelial cells. Genetic studies in man and in animal models have demonstrated an important role in the physiopathology of inflammatory diseases of CX3CR1 and CX3CL1. There is in fact much evidence to suggest a key contribution of CX3CR1 and of its ligand in the pathogenesis and progression of articular, renal, gastrointestinal and vascular inflammatory diseases (e.g. rheumatoid arthritis, lupus nephritis, diabetic nephropathy, Crohn's disease, ulcerative colitis, restenosis and atherosclerosis).
The expression of CX3CR1 is over-regulated in T cells, which are believed to accumulate in the synovium of patients suffering from rheumatoid arthritis. In addition, the expression of CX3CL1 is over-regulated in endothelial cells and fibroblasts present in the synovium of these patients. Consequently, the CX3CR1/CX3CL1 system plays an important role in controlling the type of cell and the mode of infiltration of the synovium and contributes towards the pathogenesis of rheumatoid arthritis (Nanki T. et al., “Migration of CX3CR1-positive T cells producing type 1 cytokines and cytotoxic molecules into the synovium of patients with rheumatoid arthritis”, Arthritis & Rheumatism (2002), vol. 46, No. 11, pp. 2878-2883).
In patients suffering form renal damage, the majority of the inflammatory leukocytes that infiltrate the kidneys express CX3CR1, and in particular it is expressed on two of the main cell types involved in the most common inflammatory renal pathologies and in kidney transplant rejection, T cells and monocytes (Segerer S. et al., Expression of the fractalkine receptor (CX3CR1) in human kidney diseases, Kidney International (2002) 62, pp. 488-495).
Participation of the CX3CR1/CX3CL1 system has been suggested also in inflammatory bowel diseases (IBD). In point of fact, in the case of patients suffering from IBD (e.g. Crohn's disease, ulcerative colitis), a significant increase in the production of CX3CL1 by the intestinal capillary system and a significant increase in CX3CR1-positive cells have been demonstrated, both at the circulatory level and in the mucosa (Sans M. et al., “Enhanced recruitment of CX3CR1+T cells by mucosal endothelial cell-derived fractalkine in inflammatory bowel diseases”, Gastroenterology 2007, vol. 132, No. 1, pp. 139-153).
Even more interesting is the demonstration of the key role played by the CX3CR1/CX3CL1 system in vascular damage and in particular under pathological conditions, for instance atherosclerosis and restenosis. CX3CR1 is indicated as a critical factor in the process of infiltration and accumulation of monocytes in the vascular wall, and CX3CR1 polymorphism in man is associated with a reduced prevalence of atherosclerosis, coronary disorders and restenosis (Liu P. et al., “Cross-talk among Smad, MAPK and integrin signalling pathways enhances adventitial fibroblast functions activated by transforming growth factor-1 and inhibited by Gax” Arterioscler. Thromb. Vasc. Biol. 2008; McDermott D. H. et al., “Chemokine receptor mutant CX3CR1-M280 has impaired adhesive function and correlates with protection from cardiovascular diseases in humans”, J. Clin. Invest. 2003; Niessner A. et al., Thrombosis and Haemostasis 2005).
European patent EP-B-0 382 276 describes a number of 1-benzyl-3-hydroxymethylindazole derivatives endowed with analgesic activity. In turn, European patent EP-B-0 510 748 describes, on the other hand, the use of these derivatives for preparing a pharmaceutical composition that is active in the treatment of autoimmune diseases. Finally, European patent EP-B-1 005 332 describes the use of these derivatives for preparing a pharmaceutical composition that is active in treating diseases derived from the production of MCP-1. 2-Methyl-2-{[1-(phenylmethyl)-1H-indazol-3-yl]methoxy}propanoic acid is thought to be capable of inhibiting, in a dose-dependent manner, the production of MCP-1 and TNF-α induced in vitro in monocytes from LPS and Candida albicans, whereas the same compound showed no effects in the production of cytokines IL-1 and IL-6, and of chemokines IL-8, MIP-1α, and RANTES (Sironi M. et al., “A small synthetic molecule capable of preferentially inhibiting the production of the CC chemokine monocyte chemotactic protein-1”, European Cytokine Network. Vol. 10, No. 3, 437-41, September 1999).
European patent applications EP-A-1 869 055, EP-A-1 869 056 and EP-A-1 675 862 describe 1,3-thiazolo-4,5-pyrimidine derivatives that are capable of acting as CX3CR1 receptor antagonists.
Despite the activity developed thus far, there is still felt to be a need for novel pharmaceutical compositions and compounds that are effective in the treatment of diseases based on the expression of MCP-1 and CX3CR1.
The Applicant has found, surprisingly, novel 1-benzyl-3-hydroxymethylindazole derivatives with pharmacological activity.
The Applicant has found, surprisingly, that the novel 1-benzyl-3-hydroxymethylindazole derivatives according to formula (I) of the present invention are capable of reducing the production of the chemokine MCP-1.
More surprisingly, the Applicant has found that the novel 1-benzyl-3-hydroxymethylindazole derivatives according to formula (I) of the present invention are capable of reducing the expression of the chemokine MCP-1.
Even more surprisingly, the Applicant has found that the novel 1-benzyl-3-hydroxymethylindazole derivatives according to formula (I) of the present invention are capable of reducing the expression of the receptor CX3CR1.
Thus, in a first aspect, the present invention consists of a compound of formula (I)
in which:
A may be —X1— or —X1—O—X2—, in which                X1 may be an alkyl group having from 1 to 5 carbon atoms, optionally substituted with one or more alkyl groups having from 1 to 5 carbon atoms, and        X2 may be an alkyl group having from 1 to 5 carbon atoms, optionally substituted with one or more alkyl groups having from 1 to 5 carbon atoms or one or more alkoxy groups having from 1 to 3 carbon atoms,        
Y may be hydrogen, —OH, —N(R11)(R12), —N(R11)O(R12), in which                R11 may be hydrogen, an alkyl group having from 1 to 5 carbon atoms, an alkoxy group having from 1 to 3 carbon atoms, or R11 together with R12 forms a 4- to 7-membered heterocycle,        R12 may be hydrogen, an alkyl group having from 1 to 5 carbon atoms, an alkoxy group having from 1 to 3 carbon atoms, an aryl group, a heteroaryl group, an alkylaryl group, an alkylheteroaryl group, COR′, COOR′, CON(R′)(R″) with R′ and R″, which may be identical or different each other, represented by hydrogen and an alkyl group having from 1 to 5 carbon atoms, or R12 together with R11, forms a 4- to 7-membered heterocycle,        
R1 and R2, which may be identical or different each other, may be hydrogen, an alkyl group having from 1 to 5 carbon atoms,
R3, R4 and R8, which may be identical or different each other, may be hydrogen, an alkyl group having from 1 to 5 carbon atoms, an alkoxy group having from 1 to 3 carbon atoms, a halogen atom, —OH, —N(R′)(R″), —N(R′)COR″, —CN, —CONR′R″, —SO2NR′R″, —SO2R′, nitro and trifluoromethyl; with R′ and R″, which may be identical or different each other, represented by hydrogen and an alkyl group having from 1 to 5 carbon atoms,
R5 may be hydrogen, an alkyl group having from 1 to 5 carbon atoms, an alkoxy group having from 1 to 3 carbon atoms, a halogen atom, —OH, —N(R)(R″), —N(R′)COR″, nitro and trifluoromethyl, or R5 together with one from between R6 and R7 forms a ring having 5 or 6 carbon atoms; with R′ and R″, which may be identical or different each other, represented by hydrogen and an alkyl group having from 1 to 5 carbon atoms,
R6 and R7, which may be identical or different each other, may be hydrogen, an alkyl group having from 1 to 5 carbon atoms, or together form a group C═O, or one from between R6 and R7, together with R5, forms a ring having 5 or 6 carbon atoms.
In a second aspect, the present invention relates to a pharmaceutical composition comprising the novel 1-benzyl-3-hydroxymethylindazole derivatives according to formula (I) or a pharmaceutically acceptable salt thereof together with at least one pharmaceutically acceptable vehicle.
The over-regulation and/or the increase of the expression of the above mentioned MCP-1, CX3CR1, and p40, the latest resulting consequently in IL-12 and/or IL-23 expression/production, which results in a development of a pathology and/or a disease is often referred in the art with the term “overexpression”. For the purpose of the present invention, the term expression is intended to include overexpression as known in the art.
Surprisingly, the Applicant has found that the novel 1-benzyl-3-hydroxymethylindazole derivatives according to formula (I) of the present invention may be used for the preparation of a pharmaceutical composition that is active in the treatment of diseases based on the expression of the chemokine MCP-1 and of the receptor CX3CR1.
Thus, in a third aspect, the present invention relates to the use of a compound of formula (I)
in which:
A may be —X1— or —X1—O—X2—, in which                X1 may be an alkyl group having from 1 to 5 carbon atoms, optionally substituted with one or more alkyl groups having from 1 to 5 carbon atoms, and        X2 may be an alkyl group having from 1 to 5 carbon atoms, optionally substituted with one or more alkyl groups having from 1 to 5 carbon atoms or one or more alkoxy groups having from 1 to 3 carbon atoms,        Y may be hydrogen, —OH, —N(R11)(R12), —N(R11)O(R12), in which        R11 may be hydrogen, an alkyl group having from 1 to 5 carbon atoms, an alkoxy group having from 1 to 3 carbon atoms, or R11 together with R12 forms a 4- to 7-membered heterocycle,        R12 may be hydrogen, an alkyl group having from 1 to 5 carbon atoms, an alkoxy group having from 1 to 3 carbon atoms, an aryl group, a heteroaryl group, an alkylaryl group, an alkylheteroaryl group, COR′, COOR′, CON(R′)(R″) with R′ and R″, which may be identical or different each other, represented by hydrogen and an alkyl group having from 1 to 5 carbon atoms, or R12 together with R11, forms a 4- to 7-membered heterocycle,        
R1 and R2, which may be identical or different each other, may be hydrogen, an alkyl group having from 1 to 5 carbon atoms,
R3, R4 and R8, which may be identical or different each other, may be hydrogen, an alkyl group having from 1 to 5 carbon atoms, an alkoxy group having from 1 to 3 carbon atoms, a halogen atom, —OH, —N(R′)(R″), —N(R′)COR″, —CN, —CONR′R″, —SO2NR′R″, —SO2R′, nitro and trifluoromethyl; with R′ and R″, which may be identical or different each other, represented by hydrogen and an alkyl group having from 1 to 5 carbon atoms,
R5 may be hydrogen, an alkyl group having from 1 to 5 carbon atoms, an alkoxy group having from 1 to 3 carbon atoms, a halogen atom, —OH, —N(R)(R″), —N(R′)COR″, nitro and trifluoromethyl, or R5 together with one from between R6 and R7 forms a ring having 5 or 6 carbon atoms; with R′ and R″, which may be identical or different each other, represented by hydrogen and an alkyl group having from 1 to 5 carbon atoms,
R6 and R7, which may be identical or different each other, may be hydrogen, an alkyl group having from 1 to 5 carbon atoms, or together form a group C═O, or one from between R6 and R7, together with R5, forms a ring having 5 or 6 carbon atoms,
for preparing a pharmaceutical composition for the treatment of diseases based on the expression of MCP-1 and CX3CR1.
In addition, in a fourth aspect, the present invention relates to a method for treating or preventing diseases based on the expression of MCP-1 and CX3CR1, characterized by the administration to a person in need thereof an effective amount of the compound of formula (I) previously described.